4.4.2 Output measurement for water-to-water and water-to-air units
4.4.2.1 Steady state conditions
This condition is considered obtained and maintained when all the measured quantities remain constant
without having to alter the set values, for a minimum duration of 1 h, with respect to the tolerances given in
Table 4. Periodic fluctuations of measured quantities caused by the operation of regulation and control
devices are permissible, on condition the mean value of such fluctuations does not exceed the permissible
deviations listed in Table 4.
4.4.2.2 Measurement of heating capacity, cooling capacity and heat recovery capacity
For the output measurement it is necessary to record all the meaningful data continuously. In the case of
recording instruments which operate on a cyclic basis, the sequence shall be adjusted such that a complete
recording is effected at least once every 30 s.
The output shall be measured in the steady state condition. The duration of measurement shall be not less than
35 min.
4.4.3 Output measurement for cooling capacity of air-to-water and air-to-air units
4.4.3.1 Steady state conditions
This condition is considered obtained and maintained when all the measured quantities remain constant
without having to alter the set values, for a minimum duration of 1 h, with respect to the tolerances given in
Table 4. Periodic fluctuations of measured quantities caused by the operation of regulation and control
devices are permissible, on condition the mean value of such fluctuations does not exceed the permissible
deviations listed in Table 4.
EN 14511-3:2004 (E)
15
4.4.3.2 Measurement of cooling capacity
For the output measurement it is necessary to record all the meaningful data continuously. In the case of
recording instruments which operate on a cyclic basis, the sequence shall be adjusted such that a complete
recording is effected at least once every 30 s.
The output shall be measured in the steady state condition. The duration of measurement shall be not less than
35 min.
4.4.4 Output measurement for heating capacity of air-to-water and air-to-air units
4.4.4.1 General
The test procedure consists of three periods: a preconditioning period, an equilibrium period, and a data
collection period. The duration of the data collection differs depending upon whether the heat pump’s
operation is steady state or transient.
Annex C gives a flow chart of the procedure and pictorially represents most of the different test sequences
that are possible when conducting a heating capacity test.
4.4.4.2 Preconditioning period
The test room reconditioning apparatus and the heat pump under test shall be operated until the test
tolerances specified in Table 4 are attained for at least 10 min.
A defrost cycle may end a preconditioning period. If a defrost cycle does end a preconditioning period, the
heat pump shall operate in the heating mode for at least 10 min after defrost termination prior to beginning the
equilibrium period.
It is recommended that the preconditioning period end with an automatic or manually-induced defrost cycle
when testing at application rating conditions for outdoor air stated in Table 3 and Table 9 of
EN 14511-2:2004.
4.4.4.3 Equilibrium period
The equilibrium period immediately follows the preconditioning period or the defrost cycle and a recovery
period of 10 min that ends a preconditioning period.
A complete equilibrium period is one hour in duration.
Except as specified in 4.4.4.7, the heat pump shall operate while meeting the test tolerances specified in
Table 4.
4.4.4.4 Data collection period
The data collection period immediately follows the equilibrium period.
Data shall be sampled at equal intervals that span every 30 s or less, excepted during defrost cycles as
specified below.
During defrost cycles, plus the first 10 min following defrost termination, data used in evaluating the integrated
heating capacity and the integrated power input of the heat pump shall be sampled more frequently, at equal
intervals that span every 10 s or less. When using the indoor air enthalpy method, these more frequently
sampled data include the change in indoor-side dry bulb temperature. When using the calorimeter method,
these more frequently sampled data include all measurements required to determine the indoor-side capacity.
EN 14511-3:2004 (E)
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For heat pumps that automatically cycle off the indoor fan during a defrost, the contribution of the net heating
delivered and/or the change in indoor-side dry bulb temperature shall be assigned the value of zero when the
indoor fan is off, if using the indoor air enthalpy method. If using the calorimeter test method, the integration of
capacity shall continue while the indoor fan is off.
The difference between the leaving and entering temperatures of the heat transfer medium at the indoor heat
exchanger shall be measured. For each interval of 5 min during the data collection period, an average
temperature difference shall be calculated, DTi (t). The average temperature difference for the first 5 min of
the data collection period, DTi (t=0), shall be saved for the purpose of calculating the following percent
change:
( ) ()
( ) 100
0
0
% ´ ú
û
ù
êë
é
D =
D = - D
D =
t
t t
i
i i
T
T T
T (8)
4.4.4.5 Test procedure: When a defrost cycle ends the preconditioning period
If the quantity %DT exceeds 2,5 % during the first 35 min of the data collection period, the heating capacity
test shall be designated a transient test (see 4.4.4.7). Likewise, if the heat pump initiates a defrost cycle
during the equilibrium period or during the first 35 min of the data collection period, the heating capacity test
shall be designated a transient test.
If the above conditions do not occur and the test tolerances specified in Table 2 are satisfied during both the
equilibrium period and the first 35 min of the data collection period, then the heat capacity test shall be
designated a steady-state test. Steady-state tests shall be terminated after 35 min of data collection.
4.4.4.6 Test procedure: When a defrost cycle does not end the preconditioning period
4.4.4.6.1 If the heat pump initiates a defrost cycle during the equilibrium period or during the first 35 min of
the data collection period, the heating capacity test shall be restarted as specified 4.4.4.6.3
4.4.4.6.2 If the quantity %DT exceeds 2,5 % any time during the first 35 min of the data collection period,
then the heating capacity test procedure shall be restarted as specified in 4.4.4.6.3. Prior to the restart, defrost
cycle shall occur. This defrost cycle may be manually initiated or delayed until the heat pump initiates an
automatic defrost.
4.4.4.6.3 If either 4.4.4.6.1 or 4.4.4.6.2 apply, then the restart shall begin 10 min after the defrost cycle
terminates with a new equilibrium period of one hour. This second attempt shall follow the requirements of
4.4.4.3 and 4.4.4.4 and the test procedure of 4.4.4.5.
4.4.4.6.4 If the conditions specified in 4.4.4.6.1 or 4.4.4.6.2 do not occur and the test tolerances specified in
Table 4 are satisfied during both the equilibrium period and the first 35 min of the data collection period, then
the heat capacity test shall be designated a steady-state test. Steady-state tests shall be terminated after
35 min of data collection.
4.4.4.7 Test procedure for transient tests
When, in accordance with 4.4.4.5, a heating capacity test is designated a transient test, the following
adjustments shall apply.
To constitute a valid transient heating capacity tests, the test tolerances specified in Table 5 shall be achieved
during both the equilibrium period and the data collection period. As noted in Table 5, the test tolerances are
specified for two sub-intervals. Interval H consists of data collected during each heating interval, with the
exception of the first 10 min after defrost termination. Interval D consists of data collected during each defrost
cycle plus the first 10 min of the subsequent heating interval.
The test tolerance parameters in Table 5 shall be determined throughout the equilibrium and data collection
periods. All data collected during each interval, H or D, shall be used to evaluate compliance with the Table 5
EN 14511-3:2004 (E)
17
test tolerances. Data from two or more H intervals or two or more D intervals shall not be combined and then
used in evaluating Table 5 compliance. Compliance is based on evaluating data from each interval separately.
The data collection period shall be extended until 3 h have elapsed or until the heat pump completes three
complete cycles during the period, whichever occurs first. If at an elapsed time of 3 h, the heat pump is
conducting a defrost cycle, the cycle shall be completed before terminating the collection of data. A complete
cycle consists of a heating period and a defrost period, from defrost termination to defrost termination.
